Questions tagged [clustering]

A cluster consists of a group of computers connected so that in many respects they can be viewed as a single system.

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MySQL high availability, failover and replication with Latency

We are in the process of implementing a new CMS (Drupal 6.x) that runs on MySQL. We have two data centers -- primary and secondary -- with known latency between them. We're unsure which version of ...
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4answers
14k views

CPU clock speed versus CPU core count - higher GHz, or more cores for SQL Server?

We are beginning to provision a set of physical servers for a virtual cluster of SQL Server 2016 nodes within VMware. We will be utilizing Enterprise Edition licenses. We plan on setting up 6 nodes, ...
4
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1answer
7k views

Are “Always On Failover Cluster Instances” and “SQL Server Failover Clustering” the same thing?

I'm reading documentations of SQL Server. On this page at https://docs.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/windows-server-failover-clustering-wsfc-with-sql-server, it says: ...
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2answers
8k views

Creating High Availability Cluster with PostgreSQL

I am new to database design. I have a task to create a high-availability cluster. I Googled a lot, however I haven't found any good way to do this on PostgreSQL. Where should I start and what are ...
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3answers
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MySQL H.A with automatic failover

MySQL has a lot of different highly available solutions, I would like to know what are the differences between all the current implementations, here are the implementations that look currently up to ...
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1answer
1k views

AlwaysON Availability Groups - IP address change of secondary replica node

I have a multi-subnet AlwaysON AG with one primary and one secondary replica in synchronous commit mode. Due to hardware maintenance the IP address of the secondary node will change. Is there any ...
4
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3answers
2k views

Cannot create login on cluster

I have a SQL Server 2008 R2 cluster on Win2008 R2. I am unable to add a login for the service account. Any other login I add to this instance works fine and I have been able to add the same ...
3
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1answer
538 views

is shared storage safe in Postgres if all servers are read-only?

Description of shared storage in Postgres: https://wiki.postgresql.org/wiki/Shared_Storage Related question: https://serverfault.com/a/620315/137464 Both of these make it clear that it's not safe to ...
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3answers
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Does Change Data Capture (CDC) work in a SQL Server 2012 AlwaysOn Failover Cluster Instances setup?

Does Change Data Capture (CDC) work in a SQL Server 2012 AlwaysOn Failover Cluster Instances setup? There would be two nodes in the AlwaysOn Failover Cluster Instances setup and two Domain ...
2
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1answer
56 views

Checkdb issue - Consistency error on two tables at critical database

There was a network activity last night and they were upgrading server switch. Whole network was down and we as a DBA had prepared by disabling all the jobs at DB server for replication and backup ...
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1answer
1k views

AlwaysOn AG: Current Host Server - Owner Node - Primary Instance

I'm building up a SQL Server AlwaysOn AG and I'm on the step "failover", manual and automatic: I noticed that in the Windows Server Failover Cluster a "Current Host Server" exists. My knowledge says ...
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5answers
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Why can't RDBM's cluster the way NoSQL does?

One of the big plusses for nosql DBMS is that they can cluster more easily. Supposedly with NoSQL you can create hundreds of cheap machines that store different pieces of data and query it all at ...
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4answers
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Clustering vs. transactional replication vs. availability groups

Assuming you need to make sure your application that relies on SQL Server 2012 as its database backend is available around the clock, even if one server machine fails. As a developer and not a DBA, I ...
6
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3answers
5k views

Max Memory settings on Multi-Instance SQL Server 2008 R2 Cluster

SQL Server 2008 R2 multi-instance cluster (on VMware vSphere 5.1) 2 nodes, each running 2 instances (4 instances in total) 16GB RAM per node. The only time the instances are on the same node is when ...
4
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3answers
5k views

How? SQL Cluster with multiple active nodes (not failover)

I'm building a new SQL 2008 R2 (Enterprise) Cluster that is backed by an EqualLogic iSCSI SAN. Instead of building a failover cluster (which I have done), I would instead like to setup several nodes ...
4
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1answer
906 views

How can I achieve clustering of rows without the exclusive lock and logging overhead of the `cluster` command?

The CLUSTER command on a big table can take a long time, and blocks both reads and writes to the table while it runs. I don't need the data in my table to be strictly sorted in index order, I just ...
4
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1answer
10k views

Multiple IPs registered for listener when using AlwaysOn AGs w/ multi-subnet clustering

We are testing AlwaysOn Availability Groups on a WSFC multi-subnet cluster and using dynamic DNS registration. Our issue is that sometimes the IP for the Availability Group Listener (AGL) in the ...
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2answers
2k views

SQL Server FCI installation with Mount Point permissions issues

Please help me get past this installation issue. I am trying to install a SQL Server 2016 (SP1 slipstreamed) Failover Cluster Instance (FCI) on two Windows Server 2012 R2 VMs. I have 3 cluster disks....
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1answer
1k views

Traditional failover clustering vs. Availability Groups

I'm looking into Availability Groups to see if i can benefit from them, but I struggle to understand if I can or not. Today, we are running a traditional failover cluster with around 150 databases. ...
2
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2answers
3k views

Change port number for SQL 2012 Cluster

I have been trying to change the port number of a SQL 2012 cluster with little success. I had thought that I could just do this the same way as normal through configuration manager however, even with ...
2
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2answers
1k views

Experience using ScaleArc in test or production?

Has anyone had any experience using ScaleArc? My CTO has asked my thoughts on it, and I have seen no information out there regarding real-world experiences.
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3answers
771 views

9 node percona xtradb cluster

We are looking to launch a 9 node percona xtradb cluster on Amazon where each ec2 node uses 20k iops disks. I was afraid if a 9 node cluster will work and mostly what I see is 3 node clusters. We ...
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2answers
939 views

SQL Server 2016 - Configuration Manager WMI Problem

Background: Windows Server 2016 Core SQL Server 2016 Enterprise (obviously 64-bit) Windows Failover Cluster SQL Failover Cluster I am attempting to connect to SQL Server Configuration Manager via my ...
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1answer
2k views

SQL Server 2012 Cluster Service pack 3 fail to failover node

Roughly a year ago, i had this problem with an 2008R2 cluster. I asked about it here, but i didn't grab enough logs in the process. And now i have the same problem on my 2012 failover cluster. So i'm ...
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1answer
3k views

AlwaysON Availability Groups - IP address & subnet change of secondary replica node

This is a follow up from question: AlwaysON Availability Groups - IP address change of secondary replica node Same scenario, Availability Group in synchronous commit mode, one primary and one ...
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2answers
1k views

Is it safe to run a Windows Failover Cluster Public and Heartbeat on a Single NIC?

I have a 2-Node Windows Failover Cluster (Windows Server 2016, SQL Server 2017) with a Quorum Disk Witness on fibre-connected shared storage. How important is it that the heartbeat is on its own ...
5
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1answer
13k views

Problem adding a new node to a SQL Server 2012 Failover Cluster

I tried to add a new node to SQL Server (2012 Standard) Failover, that is already installed on another node in Windows2012 Failover Cluster I have an issue with non editable field wiht input for SQL ...
5
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3answers
4k views

Port number change

We are planning on setting a static port for SQL Server 2005/2008 failover clustering. Any guide on what port to choose/select for 4 nodes of each cluster?(Active/Active) I am also thinking some ...
4
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1answer
7k views

grastate.dat with seqno -1 on a healthy cluster. Why?

We use those versions: # rpm -qa | egrep '(galera|maria)' mariadb-libs-5.5.41-2.el7_0.x86_64 mariadb-galera-common-5.5.40-6.el7ost.x86_64 mariadb-galera-server-5.5.40-6.el7ost.x86_64 mariadb-5.5.41-2....
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1answer
790 views

AlwaysOn Availability Groups: Confusion with some concepts

In Sql Server 2012, I am trying to install Failover Clustering to configure AlwaysOn Availability Groups. When I run Cluster Validation test wizard, it comes back with a lot of errors. One of them ...
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1answer
3k views

Lease Timeout VS HealthCheck Timeout - AlwaysON

After all the reading this is what I understood. Is it correct? LeaseTimeout is a simple heartbeat between SQL Server resource DLL and the SQL Server instance. HealthCheck Timeout is related to ...
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2answers
368 views

Failover Cluster Instance work without quorum

I have a environment with three nodes with installed SQL Server on them. All three nodes are parts of FCI and quorum setting is Node Majority. In start, first node is role owner, and all three nodes ...
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1answer
426 views

Cluster command locking read only queries on replica

I noticed that clustering can take a long time and lock the table entirely, even for reads. Index Organized Tables and incremental clustering would be perfect, but sadly they aren't supported by ...
1
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1answer
58 views

Any Reason to have AlwaysOn Failover Clustering in Azure Cloud?

Is there a reason to have AlwaysOn Failover Clustering when a database is in Azure Cloud? I understand the benefits having AlwaysOn Availability Groups in Azure Cloud for Database-Level protection. ...
1
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2answers
579 views

Manual failover of AAG in SQL Server 2012

Just a question regarding manual failovers. Does it matter if we use SSMS to perform the failover vs going to the Failover Cluster Manager and move the role to the secondary node? Is there a ...
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2answers
91 views

Safe backup of PXC / Galera cluster

I have 3 nodes 'master master' cluster and using PXC 5.6 But I am only using a single node for both read and write. Before using pxc, i was using standalone Mariadb 5.5 and I was taking backup using ...